LISST-Deep Instrument - Technical Specifications

The LISST-DEEP instrument obtains in-situ measurements of particle size distribution, optical transmission, and the optical volume scattering function (VSF). Using a red 670nm diode laser and a custom silicon detector, small-angle scattering from suspended particles is sensed at 32 specific log-spaced angle ranges. This measurement is post-processed to obtain sediment size distribution, volume concentration, optical transmission, and VSF. The electronics and optical configuration in the LISST-DEEP are very similar to Sequoia’s workhorse, the LISST- 100X. However, because of the extreme difficulty associated with keeping alignment under high pressure, the LISSTDEEP hardware design is radically different from the LISST-100X. This allows the LISST-DEEP to be deployed down to 3000 m and obtain reliable measurements of the in situ particle size distribution and volume concentration in waters with optical transmission up to 98.5%.